The present invention relates to the field of sign exhibiting and traffic control. More specifically, the present invention relates to signs having hinge mounted display items wherein the display items are supported by means permitting rotation along one margin thereof to facilitate exposure of the item to be displayed upon occurrence of a condition in the environment.
The orderly and safe flow of vehicular traffic is dependent on the proper functioning of a variety of traffic control devices. Traffic control devices range in complexity from simple placard-type signs to combination electric signal lights and vehicle sensors. The development and use of this variety of display devices is not just to control the flow of traffic, but also to advise of hazardous road conditions, such as curves, construction, road icing and the like. However, most display devices are static, in that they do not automatically sense and respond to an unplanned change in a condition of their environment which could impact the orderly flow of traffic or represent a new hazard.
The field has been and continues to be motivated to provide condition responsive traffic control devices. Typical examples of such devices include variable timer circuits preset to control signal light cycling intervals according to expected rush-hour and non rush-hour traffic volumes, and embedded road surface vehicle sensors for initiating a signal light cycle. Generally, these condition responsive control devices respond to an unplanned change in the condition of the environment, such as a power outage, flooding, freezing temperature or the like. Specialty traffic control devices have been developed to try to address the problem of certain unplanned changes in the environment which affect the orderly flow of traffic or represent potential hazards. For example, Wys (U.S. Pat. No. 5,504,481) is a recent patent for a xe2x80x9cfail-safexe2x80x9d stop light apparatus which covers the face of a traffic light with a warning sign when electrical power to the light fails. Upon restoration of power, the Wys device retracts to uncover the face of the light. The Wys device is relatively complex and requires two separate biasing and electromagnetic latching mechanisms to accomplish its utility. Kerr, Jr. (U.S. Pat. No. 3,863,214) is an earlier example of a device designed to address the same problem of a power outage to a traffic signal light. The Kerr device deploys a placard mounted at the end of a pivot arm from behind the signal light when power fails, displaying an alternative traffic control sign. Another example of a traffic control device responsive to a loss of electrical power to a signal light is disclosed by Karp (U.S. Pat. No. 4,642,605). The Karp device is relatively simple, but unlike the Wys and Kerr devices, it in not taught as retracting after power is restored to the signal light.
Each of the Wys, Kerr and Karp devices are useful for their stated purpose. However, the only condition to which they are automatically responsive is presence or absence of electrical power. Additionally, each of these devices is also required to be physically attached to the traffic signal light for which they serve as an alternative display device. It would be beneficial to have a relatively simple traffic control device that can be readily adapted to automatically respond to a variety of environmental conditions (in addition to loss of electrical power), and can be mounted and displayed other than physically attached to a traffic signal light.
The present invention is a condition responsive traffic sign device for directing pedestrian and/or vehicular traffic. The present device presents alternative sign items depending on a condition in the environment in which it is posted, a sign item being an advisory message or symbol for display to vehicular and/or pedestrian traffic in the area.
The present device is comprised of a vertically disposed placard. The placard has two sections, one disposed over the other. The upper section of the placard is a xe2x80x9cfixedxe2x80x9d section. It is fixed in that it is the section of the placard that is attached to the pole, standard or other mount on which the device is posted. The lower section of the placard is a xe2x80x9cpivotablexe2x80x9d section. Each section has a perimeter edge, and front surface and back surfaces. A pivot mechanism connects the bottom perimeter edge of the fixed section with the top perimeter edge of the pivotable section. The pivot mechanism allows the front surface of the pivotable section to rotate and fold flat against the front surface of the fixed section. A catch mechanism is disposed between the fixed section and the pivotable section. The catch mechanism releaseably holds the front surface of the pivotable section against a bias flat against the front surface of the fixed section, preventing the pivotable section from unfolding under the force of the bias. A controller is attached to the back surface of the fixed section of the placard. The controller may be mechanically operated, electric powered, or a combination of the two. The controller senses when the condition to which the sign is responsive occurs, and then releases the catch mechanism from holding the pivotable section flat against the fixed section. This allows the pivotable section to unfold under the force of the bias to display the front surfaces of both sections of the placard substantially aligned in a vertical plane. An electrical power source is operatively connected to the controller. A mounting means is also disposed on the back surface of the fixed section. The mounting means attaches the fixed section of the placard in a proximately vertical orientation to a pole, standard or other suitable mount.
When the placard is in an unfolded configuration, the front surfaces of the fixed and pivotable sections of the placard together display a first sign item. However, when the placard is in its folded configuration, it is the back surface of the pivotable section that is presented and can display a second sign item. Therefore, alternative sign items may be displayed, depending on whether the sections of the placard are folded or unfolded.
The pivot mechanism may be accomplished by any of a number of means known to one of ordinary skill in the art. Typically, a pivot means comprises the fixed and pivotable section of the placard being interconnected by at least one mutual rod or pin about which the sections are rotatable. For example, any of a variety of hinges are selectable and adaptable for practice of the pivot means for interconnecting the fixed and pivotable sections of the placard. The pivot mechanism may further include a spring to bias the pivotable section of the placard relative to the fixed section in an unfolded configuration. Other means for biasing the pivotable section of the placard relative to the fixed section in an unfolded configuration may be included in the present device. The purpose of this biasing means is to facilitate the initial unfolding of the two sections of the placard relative to each other. Depending on the type of pivot mechanism used, if the device has not been activated in a long time, the pivot may not operate as freely as desired, and an initial bias to facilitate its operation could be beneficial. Additionally, in inclement weather, icing of the folded surfaces may occur, and an initial bias to break any adhesion of the folded surfaces may facilitate the operation of the device.
The catch mechanism comprises a latch and catch combination. The latch is mounted on one section of the placard and the catch is mounted on the other. The latch on one section is disposed to releaseably engage the catch on the other section and prevent the rotation of the sections about the pivot mechanism. Typically, the latch is mounted on the fixed section of the placard and the catch is on the pivotable section of the placard. The catch mechanism may be electrically or mechanically operated to cause the latch to disengage the catch. Examples of catch mechanisms adaptable for practice in the present invention include catch and pawl combinations, which may be either mechanically or electrically operated, and electromagnets. Catch mechanisms are known in the art and are selectable by the ordinary skilled artisan for practice in the present invention.
The controller detects or senses the condition to which the sign is responsive. The controller may inherently detect the condition (such as loss of power), or it may include an actuator/sensor combination for this purpose. Upon detecting the condition, the controller releases the catch mechanism and allows the pivotable section to unfold to display the front surfaces of both sections of the placard. The controller may be designed to operate mechanically or electro-mechanically, depending on the condition to which the controller is responsive and the design of the means of detecting the condition. The controller is in operative communication with the catch mechanism and acts to release the catch mechanism upon detecting the condition to which the sign is responsive. Where the controller comprises an actuator/sensor combination, the actuator feature is in operative communication with the sensor and the catch mechanism, the actuator for releasing the catch mechanism in response to the sensor detecting a condition to which the sign is responsive.
Typically, the condition to which the present device is responsive is a change in the environment of the sign. Changes in the environment of the sign to which the controller may be responsive include temperature, electrical power, electrical parameter and signal transmission, and moisture. For example, the controller may detect or sense a loss of electrical power, a drop in temperature below freezing, moisture (precipitation) or water (flooding) in the environment, or the presence of an activation signal transmission.
An electrical power source is operatively connected to the controller in those embodiments of the present invention wherein the controller is electro-mechanical. The power source provides electrical power to the controller to energize those features and functions of the controller that require electricity. The power source can be as simple as a connection to an external electrical line, it can be an internal power supply circuit, or a combination of the two. An example of an internal power supply circuit is the combination of a solar panel with a charging circuit and a storage battery. An example of a combination power source is a charging circuit and a storage battery combined with a switching circuit connected to an external electrical line.
The present invention includes a means of mounting the device to a pole, sign standard or other sign posting means. The mounting means may be accomplished by utilizing any of a number of methods and fasteners known to one of ordinary skill in the art, including bolts, screws, straps and other types of fasteners. Typically, in accomplishing the mounting means, a fastener is combined with a standoff at the back surface of the fixed section for attaching the device to a pole or standard. The housing of the controller my serve as a standoff for attaching the device to a pole or standard. Additionally, when gravity provides bias for unfolding the sections of the placard, the standoff is disposed to mount the fixed section of the placard in an orientation that is sufficiently inclined from vertical to allow gravity to bias the pivotable section to rotate away from the fixed section when the catch mechanism is released.
Optionally, a folding mechanism may be incorporated into the present device. The folding mechanism comprises a motor assembly to rotate the pivotable section and fold it flat against the fixed section, causing the catch mechanism to re-engage. The folding mechanism is activated upon termination of the condition to which the sign is responsive.
As a further option, the present condition responsive traffic sign can include an electrically powered light source disposed on the front surface of the placard and operatively connected to the power source via the controller. The light source would be energized upon the controller releasing the catch mechanism and displayed at the front surfaces of the unfolded sections of the placard.